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<h4 class="subsection" id="PRU-Built_002din-Functions-1"><span>6.60.27 PRU Built-in Functions<a class="copiable-link" href="#PRU-Built_002din-Functions-1"> &para;</a></span></h4>

<p>GCC provides a couple of special builtin functions to aid in utilizing
special PRU instructions.
</p>
<p>The built-in functions supported are:
</p>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-_005f_005fdelay_005fcycles"><span class="category-def">Built-in Function: </span><span><code class="def-type">void</code> <strong class="def-name">__delay_cycles</strong> <code class="def-code-arguments">(constant long long <var class="var">cycles</var>)</code><a class="copiable-link" href="#index-_005f_005fdelay_005fcycles"> &para;</a></span></dt>
<dd><p>This inserts an instruction sequence that takes exactly <var class="var">cycles</var>
cycles (between 0 and 0xffffffff) to complete.  The inserted sequence
may use jumps, loops, or no-ops, and does not interfere with any other
instructions.  Note that <var class="var">cycles</var> must be a compile-time constant
integer - that is, you must pass a number, not a variable that may be
optimized to a constant later.  The number of cycles delayed by this
builtin is exact.
</p></dd></dl>

<dl class="first-deftypefn">
<dt class="deftypefn" id="index-_005f_005fhalt"><span class="category-def">Built-in Function: </span><span><code class="def-type">void</code> <strong class="def-name">__halt</strong> <code class="def-code-arguments">(void)</code><a class="copiable-link" href="#index-_005f_005fhalt"> &para;</a></span></dt>
<dd><p>This inserts a HALT instruction to stop processor execution.
</p></dd></dl>

<dl class="first-deftypefn">
<dt class="deftypefn" id="index-_005f_005flmbd"><span class="category-def">Built-in Function: </span><span><code class="def-type">unsigned int</code> <strong class="def-name">__lmbd</strong> <code class="def-code-arguments">(unsigned int <var class="var">wordval</var>,                     unsigned int <var class="var">bitval</var>)</code><a class="copiable-link" href="#index-_005f_005flmbd"> &para;</a></span></dt>
<dd><p>This inserts LMBD instruction to calculate the left-most bit with value
<var class="var">bitval</var> in value <var class="var">wordval</var>.  Only the least significant bit
of <var class="var">bitval</var> is taken into account.
</p></dd></dl>

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